A comparison of 25 G and 27 G Whitacre needles for Caesarean section

Smith, E. A.; Thorburn, J.; Duckworth, R. A.; Reid, Jeremy

doi:10.1111/j.1365-2044.1994.tb04258.x

Cited by 44 publications

(39 citation statements)

References 7 publications

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“…Smith & Ruck (1997) reported a global metallicity for the Hyades cluster of ½Fe=H ¼ þ0:13 based on values determined for individual dwarfs and giants from highresolution spectra. Smith (1999) derived similar values for the Hyades K0 giants Tau and Tau. On the basis of low-resolution X-ray CCD spectra, Still & Hussain (2003) reported coronal abundances showing only a very mild Fe abundance depletion relative to photospheric estimates, together with evidence of an inverse FIP effect.…”

Section: V471 Tausupporting

confidence: 61%

The Coronae of AB Doradus and V471 Tauri: Primordial Angular Momentum versus Tidal Spin‐up

García-Álvarez

Drake

Lin

et al. 2005

ApJ

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The zero-age main-sequence star AB Dor and the K dwarf component of the V471 Tau close binary have essentially identical rotation rates and spectral types. An analysis of their high-resolution Chandra X-ray spectra reveals remarkably similar coronal characteristics in terms of both temperature structure and element abundances. Both stars show depletions of low first ionization potential (FIP) elements by factors of $3, with higher FIP elements showing more mild depletions. No evidence for enhancements of very low FIP (<7 eV) elements, such as Na, Al, and Ca, as compared to other low-FIP elements, was found. The abundance anomaly pattern for AB Dor and V471 Tau is similar to, although less extreme than, the abundance anomalies exhibited by active RS CVn-type binaries. While we find statistically significant structure in the underlying differential emission measure distributions of these stars over narrow temperature intervals, this structure is strongly dependent on the lines used in the analysis and is probably spurious. On the basis of their X-ray similarities, we conclude that the exact evolutionary state of a star has little effect on coronal characteristics and that the parameters that dominate coronal structure and composition are simply the rotation rate and spectral type.

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Section: V471 Tausupporting

confidence: 61%

The Coronae of AB Doradus and V471 Tauri: Primordial Angular Momentum versus Tidal Spin‐up

García-Álvarez

Drake

Lin

et al. 2005

ApJ

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“…The effective temperatures, surface gravities, metallicities, and bolometric fluxes of and γ Tau have recently been determined through combining the infra-red flux method with modelling of high-resolution spectra using MARCS model atmospheres (Table B.1; Smith & Ruck 1997;Smith 1999). Luminosities for both stars can be obtained by combining their bolometric fluxes with parallaxes; results for Hipparcos trigonometric and secular parallaxes are listed in Table B.1 under Smith & Ruck (1997) and Smith (1999), respectively.…”

Section: Summary and Discussionmentioning

confidence: 99%

A Hipparcos study of the Hyades open cluster

Bruijne¹,

Hoogerwerf²,

Zeeuw³

2001

A&A

166

175

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Abstract. Hipparcos parallaxes fix distances to individual stars in the Hyades cluster with an accuracy of ∼6 percent. We use the Hipparcos proper motions, which have a larger relative precision than the trigonometric parallaxes, to derive ∼3 times more precise distance estimates, by assuming that all members share the same space motion. An investigation of the available kinematic data confirms that the Hyades velocity field does not contain significant structure in the form of rotation and/or shear, but is fully consistent with a common space motion plus a (one-dimensional) internal velocity dispersion of ∼0.30 km s −1 . The improved parallaxes as a set are statistically consistent with the Hipparcos parallaxes. The maximum expected systematic error in the proper motion-based parallaxes for stars in the outer regions of the cluster (i.e., beyond ∼2 tidal radii ∼20 pc) is < ∼ 0.30 mas. The new parallaxes confirm that the Hipparcos measurements are correlated on small angular scales, consistent with the limits specified in the Hipparcos Catalogue, though with significantly smaller "amplitudes" than claimed by Narayanan & Gould. We use the Tycho-2 long time-baseline astrometric catalogue to derive a set of independent proper motion-based parallaxes for the Hipparcos members. The new parallaxes provide a uniquely sharp view of the three-dimensional structure of the Hyades. The colour-absolute magnitude diagram of the cluster based on the new parallaxes shows a well-defined main sequence with two "gaps"/"turn-offs". These features provide the first direct observational support of Böhm-Vitense's prediction that (the onset of) surface convection in stars significantly affects their (B − V ) colours. We present and discuss the theoretical Hertzsprung-Russell diagram (log L versus log T eff ) for an objectively defined set of 88 high-fidelity members of the cluster as well as the δ Scuti star θ 2 Tau, the giants δ 1 , θ 1 , , and γ Tau, and the white dwarfs V471 Tau and HD 27483 (all of which are also members). The precision with which the new parallaxes place individual Hyades in the Hertzsprung-Russell diagram is limited by (systematic) uncertainties related to the transformations from observed colours and absolute magnitudes to effective temperatures and luminosities. The new parallaxes provide stringent constraints on the calibration of such transformations when combined with detailed theoretical stellar evolutionary modelling, tailored to the chemical composition and age of the Hyades, over the large stellar mass range of the cluster probed by Hipparcos.

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“…Thirty-nine studies (16 RCT, [10][11][12]14,[16][17][18][19][20][21]23,24,26,[28][29][30] ten cohort studies, [33][34][35][36][38][39][40][41][42][43] and 13 case series 45,[47][48][49][50][51][53][54][55][56][57][58][59][60] ) contained data on frequency of ADP or PDPH (Table I). Figures 1 to 3 summarize the meta-analyses of ADP and PDPH risks for different epidural and spinal needles.…”

Section: Dp and Pdph Ratesmentioning

confidence: 99%

PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies

Choi

Galinski

Takeuchi

et al. 2003

Can J Anesth/J Can Anesth

326

182

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P Pu ur rp po os se e: : Postdural puncture headache (PDPH) is an iatrogenic complication of neuraxial blockade. We systematically reviewed the literature on parturients to determine the frequency, onset, and duration of PDPH. M Me et th ho od ds s: :Citations on PDPH in the obstetrical population were identified by computerized searches, citation review, and hand searches of abstracts and conference proceedings. Citations were included if they contained extractable data on frequency, onset, or duration of PDPH. Using meta-analysis, we calculated pooled estimates of the frequency of accidental dural puncture for epidural needles and pooled estimates of the frequencies of PDPH for epidural and spinal needles.R Re es su ul lt ts s: : Parturients have approximately a 1.5% [95% confidence interval (CI) 1.5% to 1.5%) risk of accidental dural puncture with epidural insertion. Of these, approximately half (52.1%; 95% CI, 51.4% to 52.8%) will result in PDPH. The risk of PDPH from spinal needles diminishes with small diameter, atraumatic needles, but is still appreciable (Whitacre 27-gauge needle 1.7%; 95% CI, 1.6% to 1.8%). PDPH occurs as early as one day and as late as seven days after dural puncture and lasts 12 hr to seven days. C Co on nc cl lu us si io on n: : PDPH is a common complication for parturients undergoing neuraxial blockade. Objectif : Les céphalées post-ponction durale (CPPD) sont une complication iatrogène du bloc neuraxial. Une revue systématique des publications sur les parturientes a permis de déterminer la fréquence, le délai d'installation et la durée des CPPD. Méthode : Les citations sur les CPPD dans la population obstétricale ont été repérées par des recherches informatisées, la revue des références et des recherches manuelles de résumés et de comptes rendus de conférences. Les références retenues devaient comporter des données sur la fréquence, le délai d'installation et la durée des

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A comparison of 25 G and 27 G Whitacre needles for Caesarean section

Abstract: Summary Spinal needles with a pencil-point tip and those of a finer

Cited by 44 publications

References 7 publications

The Coronae of AB Doradus and V471 Tauri: Primordial Angular Momentum versus Tidal Spin‐up

The Coronae of AB Doradus and V471 Tauri: Primordial Angular Momentum versus Tidal Spin‐up

A Hipparcos study of the Hyades open cluster

PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies

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